Apparatus for testing telephone-wires.



No. 855,117. I 4 PATENTED MAY 28,'190'7.

' J. M. MILLER & 0. J. MURRAY.

APPARATUS EOE TESTING TELEPHONE WIRES.

APPLICATION FILED JUNE 20,1906.

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UNITED STATES. PATENT OFFICE JAMEs M. MILLER AND oLINToN J. MURRAY, orNEWTOWN SQUARE,

PENNSYLVANIA.

APPARATUS FOR TESTING TELEPHONE-WIRES.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed June 20, 1906. Serial No. 322,511-

To all whom it may concern:

Be it known that we, JAMEs M. MILLER and CLINTON J. MURRAY, citizens ofthe United States, residing at Newtown Square, county of Delaware, andState of Pennsylvania, have invented a,certain new and usefulImprovement in Apparatus for Testing Telephone-Wires, of which thefollowing is a specification.

Our invention relates to a new and useful improvement in apparatus fortesting telephone lines, and has for its object to provide anexceedingly simple and effective device of this description by which theline-man may readily communicate with a central station for the purposeof testing a given length of line wire and. in which the transmitterwill have a battery included in its local circuit so as to avoid thedifiiculty heretofore experienced in having to transmit the speech bythe power of voice.

With these ends in view, this invention consists in the details ofconstruction and combination of elements hereinafter set forth and thenspecifically designated by the claims.

In order that those skilled. in the art to which this inventionappertains may understand how to make and use the same, we will describeits construction in detail, referring by letter to the accompanyingdrawing forming a part of this specification, in which a diagram isshown of our improvement, the

case being omitted so as to clearly illustrate the form of wire.

Referring to this drawing A represents a neto and bell circuit E inwhich is located the while the opposite side of this jack is connectedby the wire L to the post B.

M represents the transmitter jack, one side of which is connected by thewire N to the primary coil 0 while the opposite side of this jack isconnected by the wire P to the'battery Q, the opposite side of thelatter being connected by the wire R to the wire J, and as the wire J isalso connected with the primary coil a local circuit will be provided inwhich the transmitter jack, primary coil and battery are included.

A transmitter and receiver having been connected with the jack and theposts A and B connected with the line wires or the line wire and theground it is only necessary to depress the switch D to put the bell andmagneto in circuit with the line wire, when by operating the magneto acurrent will be thrown to line, thus signaling the central station andan answer from the station will sound the bell F. Now by releasing theswitch D the bell and magneto circuit will be cut out and communicationmay be had between the central station and the line-man through thetransmitter and receiver, the battery relieving the line-man of thenecessity of having to raise his voice to an undue pitch to transmit themessage when the distance is considerable as will be readily understood.

Heretofore testing sets for line-men have not included a battery andconsequently considerable difficulty has been experienced intransmitting a message to the central station at any distance, and undersome conditions this difliculty reaches the point of impracticability;but this difiiculty is entirely overcome by the use of our improvedtesting apparatus and a message may be as readily transmitted as throughordinary stationary telephone instruments.

Having thus fully described our invention, what we claim as new anduseful, is

In a line-mans testing set for telephone lines, a bell, a magneto, acircuit in which said bell and magneto is included, a switch for cuttingsaid bell and magneto circuit in or out of the line circuit, a receiverjack, a

circuit in which said receiver jack is included, In testimony whereof,we have hereunto 10 said last named circuit being so arranged as afliXedour signatures in the presence oltwo to be cut in or out of the lineWire circuit by subscribing Witnesses.

the switch, a secondary coil also included in the receiver jack circuit,a transmitter jack, a local circuit in which said transmitter jack 1 l lis included, a battery and a primary coil also Witnesses:

included in the last named circuit, as speci- J AOKSON DUNLAP,

fied. J. LEEK.

